JPH0444852Y2 - - Google Patents

Description

[Detailed description of the invention] <Field of industrial application> The invention is an idling continuation device for turbocharged vehicles that does not immediately stop the engine even after the ignition switch is turned off, but continues idling for a set period of time. Regarding the improvement of

<Conventional technology> Recently, the number of automobiles equipped with a turbocharger has been increasing, but in such turbocharged vehicles, if the engine is stopped immediately by turning off the ignition switch after continuous high-speed driving, the turbocharger will not be activated. It has been reported that this may cause stress to the mechanism and shorten its lifespan.

For this reason, the present applicant has conventionally decided not to stop the engine immediately after turning off the ignition switch, but for a set period of time (generally about 1 to 10 minutes).
They proposed a circuit like the one shown in Figure 3, which is designed to stop the engine after idling for a certain amount of time.

To explain this while following its operation,
Of course, while the vehicle is running, the ignition switch 11 is turned on, and the ignition load 12, which controls engine rotation, is also in operation.

When the ignition switch 11 is turned off after the vehicle is running, the power supply voltage from the vehicle-mounted battery 13 drops to zero in the circuit system after the ignition switch 11, so the voltage value changes during that transition period. When the voltage falls below a predetermined threshold, the voltage determination circuit 14 detects this, issues a start signal and operates the timer circuit 15, and only for the time Ts set in the timer circuit 15.
The base signal of transistor 16 is set to high level,
The transistor 16 is turned on.

Therefore, even if the ignition switch 11 is turned off, the ignition switch 11 is shunted by the closing of the normally open contact 18 of the relay 17 driven by the turned-on transistor 16, and the above set time Ts is reached. During this period, the ignition load 12 continues to operate and the engine is placed in an idling state.

Regarding this, strictly speaking, from the circuit shown in FIG. 3, after the ignition switch 11 is turned off, the voltage determination circuit 14 detects a drop in the power supply voltage to a predetermined potential, and based on this, the timer circuit 15 operates. However, a slight time delay is expected until the relay normally open contact 18 that shuts off the ignition switch is turned on.

However, in reality, vehicles are equipped with various electrical components, and some of these power circuits have a considerable capacity, so even if the ignition switch 11 is turned off, the capacity remains Because the potential of the power supply line does not drop suddenly due to the electric charge stored in the ignition load 12, the ignition load 12 does not become intermittent.

In this way, the ignition switch 11
The engine continues to operate even after the switch is turned off, but of course, when the set time Ts has elapsed, the output of the timer circuit 15 returns to a low level, which turns off the transistor 16 and causes the relay contact 18 to return to its normal open state. When the condition returns, the power supply to the ignition load 12 is cut off, and the engine then stops.

<Problems to be solved by the invention> The conventional circuit shown in FIG. This is the basic circuit that is the origin of the disclosed idling continuation device, and as a more practical improvement, the setting time of the timer circuit is made variable in consideration of the turbo temperature and engine operating time. Apart from various improvements, a common fundamental problem has arisen that must be considered.

As can be seen from the above explanation regarding the circuit shown in FIG. Accordingly, the moment when the ignition switch 11 changes from on to off cannot be clearly distinguished from the off operation of the ignition switch 11 when the circuit is first operated.

In other words, in the voltage determination circuit 14, the ignition switch 1 also turns off the contact 18 at this time.
1 was detected in the same way as OFF, and therefore the start signal was sent to the timer circuit 15 again.
Thereafter, it is possible that this circuit will be in a free-running state.

The present invention was basically developed in consideration of this point, and it clearly distinguishes between the ignition switch's off operation and the opening operation of the contact parallel to the ignition switch after the set time of the timer circuit has elapsed. In the latter case, the present invention aims to provide an idling continuation device for a turbocharged vehicle that does not trigger the timer circuit again.

<Means for solving the problems> In order to achieve the above object, the present invention proposes the following configuration.

A voltage determination circuit that outputs a start signal when the voltage of a specific line falls below a predetermined threshold value as the ignition switch is opened, and a voltage determination circuit that is set in advance based on the start signal of the voltage determination circuit and a timer circuit that closes a contact in parallel with an ignition switch for a period of time set in the ignition switch. A timer end detection circuit is provided that detects the end of the set time when the timer end detection circuit is output; The operation of the voltage determination circuit is effectively disabled while the detection output of the timer end detection circuit is being output. An idling continuation device for vehicles equipped with a turbocharger.

<Operation and Effects> According to the above configuration of the present invention, the contact that is opened when the set time of the timer circuit expires causes the voltage of the line monitored by the voltage determination circuit to fall below the predetermined threshold again. In some cases, the voltage determination circuit is effectively disabled by the output of the timer end detection circuit, so that the inconvenience of the timer circuit being erroneously triggered again can be prevented.

In other words, it is possible to respond correctly as expected only to the first off operation of the ignition switch, and fundamental problems such as circuit free-running can be fundamentally solved.

Note that various means for effectively disabling the voltage determination circuit can be considered; for example, by forcibly grounding the starting signal output by the timer end detection circuit as the output of the voltage determination circuit, This can be achieved by ensuring that even if the voltage determination circuit detects a contact open due to the expiration of the timer time, the start signal it generates is not applied to the timer circuit in a meaningful manner, or alternatively, the timer termination detection circuit can be This can also be done by using the output to operate a circuit that shuts off the power to the voltage determination circuit.

<Embodiment> FIG. 1 shows a preferred embodiment of an idling continuation device for a turbocharged vehicle constructed in accordance with the present invention.

However, components indicated by the same reference numerals as in FIG. 3 described above are the same components in the conventional example of FIG. 3.

In practice, the improvements of the present invention can be found in the timer expiry detection circuit 20 which monitors the output of the timer circuit 15.

The operation will be explained step by step below, but after the vehicle is running,
When the driver turns off ignition switch 11,
In the circuit system after the ignition switch 11, the power supply voltage from the vehicle-mounted battery 13 drops to zero, so during that transition period, when the voltage value falls below a predetermined threshold, the voltage judgment circuit 14 can detect this and issue a starting signal Ps of an appropriate pulse width, as shown in FIG.

This starting signal Ps triggers the timer circuit 15,
The timer circuit 15 outputs a signal that sets the base signal of the transistor 16 to a high level and turns on the transistor 16 only during the set time Ts.

Therefore, even if the ignition switch 11 is turned off, the ignition switch 11 is shunted by the closing of the normally open contact 18 of the relay 17 driven by the turned-on transistor 16, and the above set time Ts is reached. During this period, the ignition load 12 continues to operate, and the engine and turbocharger also continue to operate in an idling state.

The state of the timer circuit 15 is determined by the timer end detection circuit 2.
0, and when the time Ts set in the timer circuit 15 has elapsed, as shown in FIG. 2, for example, as shown in FIG. A timer end detection signal Pt with a long pulse width is generated.

Also, this timer end detection signal Ps is
In this embodiment, the output line of the voltage determination circuit 14 is forcibly grounded via the diode 21 illustrated in FIG.

Therefore, as described above, the time Ts set in the timer circuit 15 has elapsed, the transistor 16 is deenergized, and the relay 17 is restored.
Normally open contact 1 in parallel with ignition switch 11
8 returns to the normally open state, voltage determination circuit 1
4, as shown in Figure 2, even if the starting signal Ps is issued again, this signal Ps is actually
is pulled to ground and will not retrigger timer circuit 15.

Of course, such a method for disabling the voltage determination circuit 14 is only an example, and is not limited to this, and any means that can effectively disable it may be adopted according to the gist of the present invention.

For example, the timer end signal Pt issued by the timer end detection circuit 20 may operate a circuit that cuts off power supply to the voltage determination circuit 14 while the timer end signal Pt continues.

Also, as mentioned earlier regarding the conventional example, if you read only the illustrated circuit system as it is, strictly speaking, after the ignition switch 11 is turned off, the voltage determination circuit 1
4 detects a drop in the power supply voltage to a predetermined potential, the timer circuit 15 operates based on this, and there is a slight time delay until the normally open relay contact 18 that shuts off the ignition switch is closed. should be expected.

However, in reality, vehicles are equipped with various electrical components, such as audio amplifier amplifiers, whose power supply circuits have a considerable capacity, so the ignition switch 11
Even if the ignition load 12 is turned off, the potential of the power supply line does not drop suddenly due to the charges stored in these capacitors, so there is no risk that the ignition load 12 will become intermittent.

In addition, as for the timer circuit, as seen in the previously-mentioned examples of the applicant's previous applications, the set time Ts may be variable depending on the situation or manually. You are completely free to modify this part. It is also conceivable to change the relay 17 etc. to a semiconductor switch circuit.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a preferred embodiment of the idling continuation device for a vehicle equipped with a turbocharger according to the present invention, Fig. 2 is an explanatory diagram of the operation of the device shown in Fig. 1, and Fig. 3 is a conventional vehicle equipped with a turbocharger. FIG. 2 is a schematic configuration diagram of an idling continuation device for use in a vehicle. In the figure, 11 is an ignition switch, 12 is an ignition load, 13 is a battery, 14 is a voltage determination circuit, 15 is a timer circuit, 16 is a transistor, 17 is a relay, and 18 is for selectively shutting off the ignition switch. The contact point 20 is a timer end detection circuit.

Claims (1)

[Claims for Utility Model Registration] A voltage determination circuit that outputs a starting signal when the voltage of a specific line falls below a predetermined threshold value as the ignition switch is opened; An idling continuation device for a vehicle equipped with a turbocharger, comprising a timer circuit that closes a contact parallel to an ignition switch for a preset time based on the start signal; after the timer circuit is activated; is provided with a timer end detection circuit that detects the end of the set time when the timer circuit set time elapses; while the detection output of the timer end detection circuit is being output, the operation of the voltage determination circuit is effectively controlled. An idling continuation device for a vehicle equipped with a turbocharger, characterized by: